OSPF Configuration 7th page 464

[nemiath]

While configuring router Corp with OSPF two possible scenarios are given for configuring a network:

A) network 10.1.1.1 (interface ip) 0.0.0.0 area 0
B) network 10.1.0.0 0.0.255.255 area 0

Wouldn't that be correct also and if not why?

C) network 10.1.1.0 0.0.0.255 area 0

Thanks.

[Big Evil]

Both do the same thing -

10.1.1.1 0.0.0.0 - means 10.1.1.1/32 - so only this IP address will be in the OSPF table. In the example there is five different subnet.

But as mentioned - a summary of those addresses is used -

10.1.0.0/16 - with the wildcard mask of 0.0.255.255 you are saying any host in the range 1 - 255 for both the third and forth octet.

In your C example -

network 10.1.1.0 0.0.0.255 area 0

You are saying IP address range 10.1.1.0/24, so only IP address range 10.1.1.0 - 10.1.1.255 would be used. The other network (10.1.2x - 10.1.5.x) would not be part of the OSPF process

HTH -